A Comparison of Long-Term Outcomes of Computer-Navigated and Conventional Total Knee Arthroplasty: A Meta-Analysis of Randomized Controlled Trials

Maintaining the Physiological Lateral Flexion Gap in the Kinematically Aligned TKA Does Not Compromise Clinical Outcomes at One-Year Follow-Up

Background: Instability is a common cause of (total knee arthroplasty) TKA failure, which can be prevented by achieving proper gap balance during surgery. There is no consensus on the ideal gap balance in TKA, and different alignment philosophies result in varying soft-tissue tightness. Traditional TKA aims for symmetric compartment balance, while kinematic alignment (KA) restores anatomy and accepts asymmetric flexion gaps. This study evaluated the impact of these philosophies on the flexion gap balance and clinical outcomes. Methods: A retrospective review of 167 patients who received true or restricted KA robotic-assisted TKA with at least one year of follow-up was conducted. The groups were based on intraoperative flexion gap differences: symmetric (0-1 mm) (n = 94) and asymmetric (2-5 mm) (n = 73). Results: Preoperative demographics and postoperative clinical and functional scores were compared. Both groups were similar in demographics and preoperative scores. True KA alignment was more likely to result in an asymmetric flexion gap, while restricted KA produced symmetric gaps. Conclusions: The study found no adverse effects from the physiological asymmetric flexion gap, with clinical and functional outcomes comparable to symmetric gaps. A 5 mm difference between the medial and lateral gap width did not negatively impact the outcomes. True KA more frequently results in a physiological asymmetric flexion gap.

Clinical and Radiological Outcomes of Computer-Assisted Navigation in Primary Total Knee Arthroplasty for Patients with Extra-articular Deformity: Systematic Review and Meta-Analysis

Background

Computer-assisted navigation surgery (CAS) during primary total knee arthroplasty (TKA) may help improve outcomes for patients with extra-articular deformity (EAD); however, this has not been extensively studied. Therefore, we aimed to investigate the clinical and radiological outcomes following primary TKA using CAS in patients with EAD.

Methods

We searched Medline, Embase, and the Cochrane Library up to March 3, 2023 for studies investigating surgical outcomes of using the navigation system for TKA to treat patients with EAD. From 14 studies, 539 knees with EAD that underwent navigation TKA were enrolled. We investigated the knee range of motion (ROM), outcome scores at final follow-up (Knee Society Score [KSS] and Knee Functional Score [KFS]), and pre- and postoperative mechanical hip-knee-ankle (mHKA) angle using lower extremity scanogram. The meta-analysis was based on the single-arm method, and all data were pooled using a random-effects model.

Results

Following our meta-analyses, the mean knee ROM changed from 87.0° (95% confidence interval [CI], 75.9°-98.1°) preoperatively to 109.4° (95% CI, 97.9°-120.8°) postoperatively. The adjusted KSS was 93.45 points (95% CI, 88.36-98.54 points), and the adjusted KFS was 91.57 points (95% CI, 86.80-96.33 points) in knees with EAD that underwent CAS-TKA. As a radiological outcome, the mHKA angle changed from 169.53° (95% CI, 166.90°-172.16°) preoperatively to 178.81° (95% CI, 178.31°-179.30°) postoperatively.

Conclusions

CAS-TKA yielded positive clinical results and demonstrated a satisfactory alignment of the lower limb's mechanical axis. CAS-TKA showed promise for primary TKA procedures, demonstrating favorable clinical and radiological outcomes even in complex cases involving EAD.

Long-Term Outcomes of High-Flexion Design Total Knee Arthroplasty with a Short Posterior Flange

Background

The purpose of this study was to evaluate the clinical and radiological outcomes of high-flexion total knee arthroplasty (TKA) using Vega Knee System (B. Braun, Aesculap) at a long-term follow-up and to analyze the implant survivorship.

Methods

We enrolled 165 patients (232 knees) with a minimum 7-year follow-up after TKA (VEGA Knee System). For clinical assessment, range of motion (ROM), Knee Injury and Osteoarthritis Outcome Score (KOOS), and Western Ontario and McMaster University Osteoarthritis Index (WOMAC) were used. For radiologic assessment, hip-knee-ankle angle, component position, and the existence of radiolucent lines and loosening were used. Survival analysis was conducted using the Kaplan-Meier method.

Results

The mean follow-up period was 9.8 years. The mean ROM increased from 124.4° to 131.4° at the final follow-up. The WOMAC score decreased from 38.5 to 17.4 at the final follow-up (p < 0.001). All 5 subscales of the KOOS improved at the final follow-up (all subscales, p < 0.001). Revision TKA was performed in 10 cases (4.3%), which included 9 cases of aseptic loosing and 1 case of periprostatic joint infection. Of the 9 aseptic loosening cases (3.9%), 8 cases (3.4%) were loosening of the femoral component and 1 case (0.4%) was loosening of the tibial component. When revision for any reason was considered an endpoint, the 10-year survivorship was 96.2% (95% confidence interval [CI], 93.9%-98.5%). On the other hand, when revision for aseptic loosening was considered the endpoint, the 10-year survivorship was 96.6% (95% CI, 94.4%-98.8%).

Conclusions

The Vega Knee System provided good clinical results in the long-term follow-up period. Although the VEGA Knee System showed acceptable implant survivorship, loosening of the femoral component occurred in about 3.4% of the patients. For more accurate evaluation of the survivorship of high-flexion design TKA with a short posterior flange, it is necessary to conduct more long-term follow-up studies targeting diverse races, especially Asians who frequently perform high-flexion activities.

No Benefit of Robotic-Assisted over Computer-Assisted Surgery for Achieving Neutral Coronal Alignment in Total Knee Arthroplasty

The use of robotic-assisted surgery (RAS) in total knee arthroplasty (TKA) is becoming increasingly popular due to better precision, potentially superior outcomes and the ability to achieve alternative alignment strategies. The most commonly used alignment strategy with RAS is a modification of mechanical alignment (MA), labeled adjusted MA (aMA). This strategy allows slight joint line obliquity of the tibial component to achieve superior balancing. In the present study, we compared coronal alignment after TKA using RAS with aMA and computer-assisted surgery (CAS) with MA that has been the standard in the center for more than 10 years. We analyzed a prospectively collected database of patients undergoing TKA in a single center. Lateral distal femoral angle (LDFA) and medial proximal tibial angle (MPTA) were compared for both techniques. In 140 patients, 68 CASs and 72 RASs, we observed no difference in postoperative measurements (median 90 degrees for all, LDFA p = 0.676, MPTA p = 0.947) and no difference in outliers <2 degrees (LDFA p = 0.540, MPTA p = 0.250). The present study demonstrates no benefit in eliminating outliers or achieving neutral alignment of both the femoral and the tibial components in robotic-assisted versus computer-assisted TKA if MA is the target. To utilize the precision of RAS, it is recommended to aim for more personalized alignment strategies. The level of evidence is level III retrospective study.

Increased Femoral Component Flexion and No Difference in Slope in Robotic- versus Computer-Assisted Total Knee Arthroplasty When Targeting Mechanical Alignment

Robotic-assisted surgery (RAS) in total knee arthroplasty (TKA) is becoming popular due to better precision, when compared with other instrumentation. Although RAS has been validated in comparison with computer-assisted surgery (CAS), data from clinical settings comparing these two techniques are lacking. This is especially the case for sagittal alignment. Whereas pure mechanical alignment (MA) aims for 0 to 3 degrees of flexion of the femoral component and 3° of posterior slope for the tibial component, adjusted MA (aMA) mostly used with RAS allows for flexing of the femoral component for downsizing and increase of slope for an increase of the flexion gap. In the present study, we compared sagittal alignment after TKA using RAS with aMA and CAS targeting MA, which has been the standard in the center for more than 10 years. We analyzed a prospectively collected database of patients undergoing TKA in a single center. Femoral component flexion and tibial slope were compared for both techniques. In 140 patients, 68 CAS and 72 RAS, we found no difference in tibial slope (p = 0.661), 1° median femoral component flexion (p = 0.023), and no difference in outliers (femur, p = 0.276, tibia, p = 0.289). RAS slightly increases femoral component flexion, but has no influence on tibial slope, when compared with CAS in TKA. If MA is the target, RAS provides no benefit over CAS for achieving the targeted sagittal alignment. LEVEL OF EVIDENCE:  Level III retrospective study.

Accuracy of a Patient-Specific Total Ankle Arthroplasty Instrumentation

BACKGROUND

Total ankle arthroplasty (TAA) is a preferred surgical option for end-stage ankle osteoarthritis; however, it is a demanding procedure with a higher historical rate of revision compared with ankle fusion. Patient-specific instrumentation (PSI) has been introduced to optimize prosthesis alignment and theoretically overall improve TAA outcomes. The goal of this study is to report on the experience and surgical outcomes of one implant with specific evaluation of the accuracy and reproducibility of the system with respect to prosthesis alignment and prediction of implant size.

METHODS

A retrospective, multicentered study involving 4 foot and ankle fellowship-trained orthopaedic surgeon's patients undergoing TAA between January 1, 2015, and December 31, 2018, using the PROPHECY PSI system.

RESULTS

80 TAA procedures were performed. On average the postoperative tibial component alignment was 89.9 (range, 86.1-96.5) degrees in the coronal plane, with a mean sagittal alignment of 88.1 (range, 81.3-96.7) degrees. The mean deviation from neutral sagittal alignment improved from 4.9 ± 3.9 degrees preoperatively to 2.7 ± 1.7 degrees postoperatively, whereas the mean coronal alignment improved from 3.3 ± 2.5 degrees to 1.3 ± 1.1 degrees. The PSI software correctly determined the tibial implant size in 70 patients (89%). Prediction of talar implant sizing was less accurate than the tibial component, with 56 patients (71%) using the predicted sized implant. The overall implant survival at a mean follow-up of 45 months (range, 27-76) was 97.5%.

CONCLUSION

We found that this PSI system accurately and reliably assisted in implant total ankle prosthesis positioning within a clinically acceptable margin and without significant outliers. Prediction of implant size was not as accurate as component orientation.

LEVEL OF EVIDENCE

Level III, retrospective study.

Clinical and Radiological Outcomes of Computer-Assisted versus Conventional Total Knee Arthroplasty at 5-Year Follow-Up: Is There Any Benefit?

Computer-assisted total knee arthroplasty (CAS) remains controversial. Some authors defend that its improvement in knee alignment and positioning positively impacts arthroplasty survival rates, while others have stated that there is minimal or no difference compared to the conventional technique (cTKA). This paper features a retrospective, single-center, single-surgeon study, evaluating CAS surgery vs. regular cTKA in patients who consecutively underwent surgery between 2015 and 2017 (60 CAS patients vs. 59 cTKA). Data collection includes surgery duration, length of stay, blood loss and both preoperative and postoperative clinical outcome evaluation using WOMAC, SF-12, Forgotten Joint Score and VAS. Radiograph evaluation includes the tibiofemoral angle, posterior condylar offset and its ratio, and notching frequency and measurement. A total of 119 patients were included: 60 in the CAS group and 59 in the cTKA. Mean follow-up was 5.61 years (Max 7.83-Min 5.02 years). No clinically relevant preoperative differences were observed between the groups. Postoperatively, both groups showed similar functional results (WOMAC, SF-12, FJS, KSS, and VAS) with similar complication rates. The CAS group had an increased surgery time by a mean of 12 min (107.02 ± 15.22 vs. 95.32 + 13.87; p = 0.00) as well as a higher notching frequency and size (40% vs. 13.60%; p = 0.013; 1.239 mm ± 1.7604 vs. 0.501 mm ± 1.4179; p = 0.031). CAS obtained similar functional, radiological, and complication rates to cTKA at the expense of increasing surgery time and notching frequency and size.

Comparing an imageless hand-held robotic-assisted system versus conventional technique for component positioning and early clinical outcomes in total knee arthroplasty

BACKGROUND

This study aimed to examine the component positioning and early clinical outcomes in total knee arthroplasty (TKA) using an imageless hand-held robotic-assisted system compared with those without robotics.

METHODS

Component positioning, hip-knee-ankle angle (HKA), and clinical outcome 1-year postoperatively were compared between 40 patients who underwent TKA with Navio (robot group) and 40 control patients who underwent TKA with a jig-based technique (manual group). The clinical outcomes evaluated were range of motion and the 2011 Knee Society Score.

RESULTS

Implantation errors in the coronal and sagittal alignments were significantly fewer in the robotic group than in the manual group. All knees in the robotic group achieved component positions within 3°. However, the HKA and clinical outcomes did not differ between the groups.

CONCLUSION

Although the accuracy of implantation in the robotic group was superior to that in the manual group, the clinical outcomes were similar.

Patients undergoing revisions for total knee replacement malposition are younger and more often female: An analysis of data from the Dutch Arthroplasty register

Background

The proportion of patients who are dissatisfied with the outcome following total knee replacement (TKR) is high. Malalignment is considered a probable cause for persistent pain, but whether this reason for revision could be the result of specific patient characteristics remains unclear. Therefore, we aim to assess whether specific patient characteristics are associated with revision for symptomatic TKR malalignment.

Methods

Data was obtained from the Dutch Arthroplasty Register (LROI), which contains data from all Dutch hospitals. All patients who underwent TKR revision surgery between 2008 and 2019 were included in this study. The (primary) reason for revision as well as patient characteristics (age, gender, ASA classification, and pre-operative patient-reported outcome measures) were abstracted. The Chi-square test for categorical variables, and ANOVA or Kruskal-Wallis for continuous variables were used to determine differences in patient characteristics between the subgroups based on reason for revision.

Results

A total of 11,044 TKR revisions were registered in The Netherlands between 2008 and 2019. Malalignment was registered as the primary reason for revision in 13% of the patients. Subgroup analyses showed that patients who underwent TKR revisions for malalignment where younger (63.8 year, SD ± 9.3) and more often female (70%) compared to other major reasons for TKR revisions.

Conclusion

Patients who had a TKR revision for malalignment were younger and more often female. This suggests that patient characteristics may play a role when reasons to perform revision surgery are considered. Surgeons should invest in the expectation management in (young) patients and inform patients of these potential risk factors as part of shared decision-making.

Decreased patient comorbidities and post-operative complications in technology-assisted compared to conventional total knee arthroplasty

PURPOSE

The use of computer-assisted and robotic surgery was developed to improve component position and outcomes of total knee arthroplasty (TKA). The goal of this study is to identify differences in patient demographics, comorbidities, and complications between technology-assisted and conventional TKA.

METHODS

A Nationwide Inpatient Sample database was used to identify patients who underwent technology-assisted and conventional TKA from 2016 to 2018. Analysed variables include demographics, length of stay (LOS), payer-status, geographic region, comorbidities, complications, and mortality. Univariate and multivariate analyses were performed to identify differences between both groups.

RESULTS

The analysis includes 2,208,434 TKA patients, of which 2,054,879 (93.05%) were conventional and 153,555 (6.95%) were technology assisted. Patients undergoing technology-assisted TKA were more likely to be older than 65 years, had higher median income quartile, and had surgery in urban teaching hospitals. Patients were less likely to undergo technology-assisted TKA if they were female gender, had Medicare payer status, were black race, were obese, were living in rural location, or had higher Charlson comorbidity score and baseline comorbidities. Technology-assisted TKA patients had shorter LOS, and fewer pulmonary and infection complications.

CONCLUSION

Patients undergoing technology-assisted TKA are being carefully selected with less baseline comorbidities, improved health, and living in urban areas. Subsequently, those carefully selected patients are discharged home, have a shorted hospital LOS, and have fewer complications compared to conventional TKA. Rural patients, black race and female gender are less likely to undergo technology-assisted TKA, further emphasizing the healthcare disparity for that segment of the population.

LEVEL OF EVIDENCE

Therapeutic level III.

The trend and future projection of technology-assisted total knee arthroplasty in the United States

BACKGROUND

As technology-assisted surgery has boosted in the last decades, we aimed to investigate the factors affecting adoption and to predict the future utilization of technology among patients who underwent total knee arthroplasty (TKA).

METHODS

Patients underwent TKA in 2017-2019 in the MarketScan Database were included. Percentage of technology-assisted surgery was calculated. Multivariable logistic regression models were performed to analyse the factors and make the prediction.

RESULTS

Of 112,161 TKA procedures, 7.2% were technology-assisted. The proportion of technology-assisted TKA is expected to reach 50% by 2032. The West showed the highest proportion of technology-assisted TKA (12.3%), while the South had the lowest (5.7%). Over time, the Midwest showed the greatest increase in technology adoption (OR = 1.26 compared to the Northeast, 95% CI [1.15, 1.38]).

CONCLUSIONS

Technology adoption rate of TKA will continue to increase for the next 20 years in the United States with a slight geographical variation.

The Reverse Fragility Index: Interpreting the Current Literature on Long-Term Survivorship of Computer-Navigated Versus Conventional TKA: A Systematic Review and Cross-Sectional Study of Randomized Controlled Trials

BACKGROUND

Despite the most recent American Academy of Orthopaedic Surgeons clinical practice guideline making a "strong" recommendation against the use of intraoperative navigation in total knee arthroplasty (TKA), its use is increasing. We utilized the concept of the reverse fragility index (RFI) to assess the strength of neutrality of the randomized controlled trials (RCTs) comparing the long-term survivorship of computer-navigated and conventional TKA.

METHODS

A systematic review was performed including all RCTs through August 3, 2021, comparing the long-term outcomes of computer-navigated and conventional TKA. Randomized trials with mean follow-up of >8 years and survivorship with revision as the end point were included. The RFI quantifies the strength of a study's neutrality by calculating the minimum number of events necessary to flip the result from nonsignificant to significant. The RFI at a threshold of p < 0.05 was calculated for each study reporting nonsignificant results. The reverse fragility quotient (RFQ) was calculated by dividing the RFI by the study sample size.

RESULTS

Ten clinical trials with 2,518 patients and 38 all-cause revisions were analyzed. All 10 studies reported nonsignificant results. The median RFI at the p < 0.05 threshold was 4, meaning that a median of 4 events would be needed to change the results from nonsignificant to significant. The median RFQ was 0.029, indicating that the nonsignificance of the results was contingent on only 2.9 events per 100 participants. The median loss to follow-up was 27 patients. In all studies, the number of patients lost to follow-up was greater than the RFI.

CONCLUSIONS

The equipoise in long-term survivorship between computer-navigated and conventional TKA rests on fragile studies, as their statistical nonsignificance could be reversed by changing the outcome status of only a handful of patients--a number that was always smaller than the number lost to follow-up. Routine reporting of the RFI in trials with nonsignificant findings may provide readers with a measure of confidence in the neutrality of the results.

LEVEL OF EVIDENCE

Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

Reduced Early Revision Surgery and Medical Complications in Computer-assisted Knee Arthroplasty Compared With Non-computer-assisted Arthroplasty

BACKGROUND

Computer assistance can help surgeons achieve mechanical accurate alignment, but the clinical effect of this technology in different arthroplasty types remains controversial because of conflicting functional outcomes, revision rates, and complication rates. The goal of this study was to compare 90-day medical complications and 1 and 2-year revision surgeries after computer-assisted patellofemoral arthroplasty, unicompartmental knee arthroplasty (CA-UKA), bicompartmental knee arthroplasty (CA-BKA), and total knee arthroplasty (CA-TKA) with non-computer-assisted procedures.

METHODS

A retrospective cohort analysis was conducted using the Mariner data set of the PearlDiver Patient Records Database from 2010 to 2018. Current Procedural Terminology codes were used to identify patients who underwent patellofemoral arthroplasty, unicompartmental knee arthroplasty, bicompartmental knee arthroplasty, and total knee arthroplasty with or without computer assistance for osteoarthritis. All included patients were followed up for 2 years. Univariate and multivariable analyses were conducted.

RESULTS

On multivariable analysis, revision within 1 year was decreased in patients who underwent computer-assisted patellofemoral arthroplasty (odds ratio [OR]: 0.541, P = 0.031), CA-UKA (OR: 0.798, P = 0.019), and computer-assisted bicompartmental knee arthroplasty (OR: 0.186, P = 0.025) compared with the same surgeries without technology assistance. CA-TKA had decreased odds of revision for aseptic loosening at 2 years (OR: 0.789, P < 0.001). CA-UKA and CA-TKA had decreased risk of overall 90-day medical complications (OR: 0.838, P < 0.001; OR: 0.903, P < 0.001, respectively) and major complications (OR: 0.750, P = 0.004; OR: 0.822, P < 0.001, respectively).

DISCUSSION

Complication rates and revision surgeries for all arthroplasty types were equivalent or more favorable when computer assistance was used during surgery. Our results quantify some early benefits to using computer assistance in total and partial knee arthroplasties.

No advantage with navigated versus conventional mechanically aligned total knee arthroplasty-10 year results of a randomised controlled trial

PURPOSE

Computer-assisted surgery (CAS) total knee arthroplasty (TKA) remains a controversial area of surgical practice. The aim of this study is to report the ten-year revision rates and patient-reported outcome measures (PROMS) of a single-blinded, prospective, randomised controlled trial comparing electromagnetically (EM) navigated and conventional TKA.

METHODS

199 patients were randomised to receive either EM navigated or conventional TKA where the aim of implantation was neutral mechanical alignment in all cases. Ten-year revision rates were collated and compared between the two intervention groups. Longitudinal PROMS data was collected prospectively at various time points up to 10 years post-operatively.

RESULTS

Over the ten-year period, there were 23 deaths (22.8%) in the EM navigation cohort and 30 deaths (30.6%) in the conventional cohort. At 10 years post-operatively, there was no statistically significant difference in all cause revision between the EM navigation and conventional cohort (4.0 vs 6.1%, p = 0.429). When analysing causes of revision that might be influenced by utilising EM navigation, there was no statistically significant difference in revisions (3.0% EM navigated vs 4.1% conventional group, p = 0.591). Patients that received navigated TKAs had improved Oxford Knee Society, American Knee Society Score and range of motion at 3 months following surgery compared to conventional TKA (p = 0.002, p = 0.032, and p = 0.05, respectively). However, from 1 to 10 years post-operatively, both interventions had equivalent outcomes.

CONCLUSION

There is no difference in revision rates or clinical outcomes comparing EM navigated versus conventional TKA at ten-year follow-up. The expected mortality rate makes it unlikely that a difference in revision rates will reach statistical significance in the future. In the setting of an experienced knee arthroplasty surgeon, it is difficult to justify the additional costs of CAS in TKA surgery.

LEVEL OF EVIDENCE

I.

Computer-Navigated and Robotic-Assisted Total Knee Arthroplasty: Increasing in Popularity Without Increasing Complications

BACKGROUND

Data on the clinical impact of computer navigation (CN) and robotic assistance (RA) in total knee arthroplasty (TKA) are mixed. This study aims to describe modern utilization trends in CN-TKA, RA-TKA, and traditionally-instrumented (TD) TKA and to assess for differences in postoperative complications and opioid consumption by procedure type.

METHODS

A national database was queried to identify primary, elective TKA patients from 2015 to 2020. Trends in procedural utilization rates were assessed. Differences in 90-day postoperative complications and inpatient opioid consumption were assessed. Multivariate regression analyses were performed to account for potential confounders.

RESULTS

Of the 847,496 patients included, 49,317 (5.82%) and 24,460 (2.89%) underwent CN-TKA and RA-TKA, respectively. CN-TKA utilization increased from 5.64% (2015) to 6.41% (2020) and RA-TKA utilization increased from 0.84% (2015) to 5.89% (2020). After adjusting for confounders, CN-TKA was associated with lower periprosthetic joint infection (P = .001), pulmonary embolism (P < .001), and acute respiratory failure (P = .015) risk compared to traditional (TD) TKA. RA-TKA was associated with lower deep vein thrombosis (P < .001), myocardial infarction (P = .013), and pulmonary embolism (P = .001) risk than TD-TKA. Lower postoperative day 1 opioid usage was seen with CN-TKA and RA-TKA than TD-TKA (P < .001). Lower postoperative day 0 opioid consumption was also seen in RA-TKA (P < .001).

CONCLUSION

From 2015 to 2020, there was a relative 13.7% and 601.2% increase in CN-TKAs and RA-TKAs, respectively. This trend was associated with reductions in hospitalization duration, postoperative complications, and opioid consumption. These data support the safety of RA-TKA and CN-TKA compared to TD-TKA. Further investigation into the specific indications for these technology-assisted TKAs is warranted.

Knee arthroplasty utilization trends from 2010 to 2019

BACKGROUND

Interest in partial knee arthroplasty procedures including unicompartmental arthroplasty (UKA), patellofemoral arthroplasty (PFA), and bicompartmental knee arthroplasty (BKA) has increased due to their bone and ligament preservation compared to total knee arthroplasty (TKA). Implant designs, changing thoughts on appropriate indications for partial knee arthroplasty, and availability of navigation also impacted the field over the last decade. The aims of this study were to evaluate trends over the last decade in utilization of 1) partial and total knee arthroplasty; and 2) computer-assistance in knee arthroplasty.

METHODS

A retrospective cohort analysis was conducted using the PearlDiver database. Patients who underwent PFA, UKA, BKA, and TKA for an indication of osteoarthritis (OA) were identified using Current Procedural Terminology (CPT) codes. Trends analysis from 2010 to 2019 was conducted to compare utilization based on procedure type and computer-assistance. Statistical analysis was conducted using Compounded Annual Growth Rates (CAGR) and linear regression.

RESULTS

From 2010 to 2019, there was a significant decrease in utilization of PFA (CAGR: -5.73 %; p = 0.011) and BKA (CAGR: -10.49 %; p = 0.013), but no significant difference in that of UKA (p = 0.224) and TKA (p = 0.421). There was a significant increase in the utilization of computer assistance for both UKA (CAGR: +19.81 %; p = 0.002) and TKA (CAGR: +3.90 %; p = 0.038), but there was no significant difference for computer-assisted PFA (p = 0.724) and BKA (p = 0.951).

CONCLUSIONS

TKA is still the most common arthroplasty procedure for OA. Decreased utilization of PFA and BKA may be explained by reported failure and revision rates for PFA and BKA compared to TKA.

Elucidation of target implant orientations with the safety range of hip rotation with adduction or abduction during squatting: Simulation based on in vivo replaced hip kinematics

Objectives: The study aimed to elucidate target cup orientation and stem anteversions to avoid impingement between the liner and stem neck even at hip rotation with adduction during the deeply flexed posture.

Methods: A computer simulation analysis was performed on 32 total hip arthroplasty patients applying patient-specific orientation of the components and in vivo hip kinematics obtained from three-dimensional analysis of the squatting motion. The anterior/posterior liner-to-neck distance and impingement were evaluated based on a virtual change in internal/external rotation (0°–60°) and adduction/abduction (0°–20°) at actual maximum flexion/extension during squatting. Cutoff values of cup orientations, stem anteversion, and combined anteversion to avoid liner-to-neck impingements were determined.

Results: The anterior liner-to-neck distance decreased as internal rotation or adduction increased, and the posterior liner-to-neck distance decreased as external rotation or adduction increased. Negative correlations were found between anterior/posterior liner-to-neck distances at maximum flexion/extension and internal/external rotation. Anterior/posterior liner-to-neck impingements were observed in 6/18 hips (18/56%) at 45° internal/external rotation with 20° adduction. The range of target cup anteversion, stem anteversion, and combined anteversion to avoid both anterior and posterior liner-to-neck impingements during squatting were 15°–18°, 19°–34°, and 41°–56°, respectively.

Conclusion: Simulated hip rotations caused prosthetic impingement during squatting. Surgeons could gain valuable insights into target cup orientations and stem anteversion based on postoperative simulations during the deeply flexed posture.

Comparison of Survival Rate and Outcomes Between Conventional and Navigation-Assisted Primary Total Knee Arthroplasty in Severe Varus Knees: A Minimum 10-Year Follow-Up

BACKGROUND

This study aimed to compare the long-term clinical and radiographic outcomes and survival rates between navigation-assisted (NAV) total knee arthroplasty (TKA) and conventional (CON) TKA in patients with preoperative severe varus deformity.

METHODS

From January 2005 to December 2011, 152 TKAs and 62 TKAs with preoperative hip-knee-ankle (HKA) angles more than 15° were enrolled in the CON-TKA and NAV-TKA group with 135.7 months follow-up. Clinical outcomes (Western Ontario and McMaster University Osteoarthritis Index and Knee Society Scores), radiographic outcomes (HKA, α, β, γ, and δ angles), and survivorship were compared between the groups.

RESULTS

The mean value of radiographic outcomes was not statistically different; however, outliers of the HKA angle were significantly higher in the CON-TKA group (18.4% versus 8.1%, P = .04). However, long-term clinical outcomes were similar between both groups. The cumulative survival rate was 96.1% in the CON-TKA group and 96.8% in the NAV-TKA group, with no difference between the groups (P = .962).

CONCLUSION

NAV-TKA showed fewer outliers in the HKA angle for severe preoperative varus deformity compared with CON-TKA. The long-term clinical outcomes and survival rates were similar between the 2 techniques. A survival rate of more than 96% was observed in both groups.

STUDY DESIGN

Level III, retrospective comparative study.

Funding has no effect on clinical outcomes of total joint arthroplasty emerging technologies: a systematic review of bibliometrics and conflicts of interest

Background

The use of new total joint arthroplasty technologies, including patient-specific implants/instrumentation (PSI), computer-assisted (CA), and robotic-assisted (RA) techniques, is increasing. There is an ongoing debate regarding the value provided and potential concerns about conflicts of interest (COI).

Methods

PRISMA guidelines were followed. PubMed, MEDLINE, and Web of Science databases were searched for total hip and knee arthroplasties, unicompartmental knee arthroplasties (UKA), PSI, CA, and RA. Bibliometric data, financial COI, clinical/functional scores, and patient-reported outcomes were assessed.

Results

Eighty-seven studies were evaluated, with 35 (40.2%) including at least one author reporting COI, and 13 (14.9%) disclosing industry funding. COI and industry funding had no significant effects on outcomes (P = 0.682, P = 0.447), and there were no significant effects of conflicts or funding on level of evidence (P = 0.508, P = 0.826). Studies in which author(s) disclosed COI had significantly higher relative citation ratio (RCR) and impact factor (IF) than those without (P < 0.001, P = 0.032). Subanalysis demonstrated RA and PSI studies were more likely to report COI or industry funding (P = 0.045). RA (OR = 6.31, 95% CI: 1.61–24.68) and UKA (OR = 9.14, 95% CI: 1.43–58.53) had higher odds of reporting favorable outcomes than PSI.

Conclusions

Author COIs (about 40%) may be lower than previously reported in orthopedic technologies/techniques reviews. Studies utilizing RA and PSI were more likely to report COI, while RA and UKA studies were more likely to report favorable outcomes than PSI. No statistically significant association between the presence of COIs and/or industry funding and the frequency of favorable outcomes or study level of evidence was found.

Level of evidence

Level V Systematic Review

Supplementary Information

The online version contains supplementary material available at 10.1186/s42836-022-00146-3.

Navigated and Robot-Assisted Technology in Total Knee Arthroplasty: Do Outcome Differences Achieve Minimal Clinically Important Difference?

BACKGROUND

In total knee arthroplasty (TKA), computer-assisted navigation (N-TKA) and robotic-assisted methods (RA-TKA) are intended to increase precision of mechanical and component alignment. However, the clinical significance of published patient-reported outcome measure (PROM) differences in comparison to conventional TKA (C-TKA) is unknown.

METHODS

A systematic review was performed to identify all studies reporting perioperative PROMs for either primary N-TKA or RA-TKA with a C-TKA comparison cohort with a minimum 1-year follow-up. Relative improvements in PROMs for the two cohorts were compared to published minimal clinically important difference (MCID) values.

RESULTS

After systematic review, 21 studies (N = 3,214) reporting on N-TKA and eight studies (N = 1,529) reporting on RA-TKA met inclusion criteria. Eighteen of 20 studies (90%) reported improved radiographic outcomes with N-TKA relative to C-TKA; five of five studies reported improved radiographic outcomes with RA-TKA relative to C-TKA. Five of 21 studies (24%) reported statistically significant greater improvements in clinical PROMs for N-TKA relative to C-TKA, whereas only two (10%) achieved clinical significance relative to MCID on a secondary analysis. One of 8 studies (13%) reported statistically significant greater improvements in PROMs for RA-TKA relative to C-TKA, whereas none achieved clinical significance relative to MCID on a secondary analysis. No studies reported a significant difference in revision rates.

CONCLUSION

While most studies comparing RA-TKA and N-TKA with C-TKA demonstrate improved radiographic alignment outcomes, a minority of studies reported PROM differences that achieve clinical significance. Future studies should report data and be interpreted in the context of clinical significance to establish patient and surgeon expectations for emerging technologies.

Peripheral Nerve Block for Hip Arthroscopy Does Not Have any Clinical Advantage Compared With Local Anesthetic Regarding Pain Management: A Meta-analysis of Randomized Controlled Trials

PURPOSE

To evaluate the efficacy of peripheral nerve block on reduction in opioid consumption and pain control after hip arthroscopy.

METHOD

To identify studies evaluating the effects of peripheral nerve block on pain control and reduction in opioid consumption in hip arthroscopy, we searched all records in the PubMed, Embase, and Cochrane Library databases until May 2021. Studies with the following characteristics were considered eligible: 1) patients who underwent a hip arthroscopy (population); 2) patients who received peripheral nerve block (intervention); 3) patients who did not receive peripheral nerve block (comparator); 4) record of total opioid consumption as a primary outcome and pain level at 1, 3 to 6, and 24 hours after surgery, patient satisfaction, and incidence of nausea and vomiting as secondary outcomes (outcomes); and 5) randomized controlled trial (study design). Data were independently extracted by two reviewers and synthesized using a random or fixed-effects model, according to the heterogeneity.

RESULTS

Eight RCTs were finally included in the meta-analysis. There were no significant differences in postoperative opioid consumption at 24 hours (standardized mean difference [SMD] = -0.091, 95% confidence interval [CI] [-0.270, 0.089]) or in visual analog scale (VAS) score at 1 (SMD = 0.299, 95% CI [-0.758, 0.160]), 3 to 6 (SMD = -0.304, 95% CI [-0.655, 0.047]), and 24 (SMD = -0.230, 95% CI [-0.520, 0.060]) hours postoperatively between the peripheral nerve block and control groups. Moreover, no significant differences were observed in patient satisfaction (SMD < 0.001, 95% CI [-0.284, 0.284]) or the incidence of nausea and vomiting (SMD = 0.808, 95% CI [0.311, 2.104]) between the two groups.

CONCLUSION

Peripheral nerve block for hip arthroscopy has no clinical advantage regarding pain management after surgery when compared with the group that received the local infiltration of analgesics without peripheral nerve block.

LEVEL OF EVIDENCE

Level II, meta-analysis of level I and II randomized controlled trials (RCTs).

Navigation and robotics improved alignment compared with PSI and conventional instrument, while clinical outcomes were similar in TKA: a network meta-analysis

PURPOSE

To achieve the desired alignment more accurately and improve postoperative outcomes, new techniques such as computer navigation (Navigation), patient-specific instruments (PSI) and surgical robots (Robot) are applied in Total Knee Arthroplasty (TKA). This network meta-analysis aims to compare the radiological and clinical outcomes among the above-mentioned techniques and conventional instruments (CON).

METHODS

A PRISMA network meta-analysis was conducted and study protocol was published online at INPLASY (INPLASY202060018). Three databases (PubMed, EMBASE and Cochrane) were searched up to June 1, 2020. Randomised controlled trials (RCTs) comparing any two of the four techniques were included. A Bayesian network meta-analysis was performed focusing on radiological and clinical outcomes. The odds ratio (OR) or mean difference (MD) in various outcomes were calculated, and the interventions were ranked by the surface under the cumulative ranking area (SUCRA) value.

RESULTS

Seventy-three RCTs were included, with a total of 4209 TKAs. Navigation and Robot could significantly reduce the occurrence of malalignment and malposition compared with PSI and CON, and Navigation could obtain higher medium-and-long-term KSS knee scores than CON. Robot had the greatest advantage in achieving the desired alignment accurately, followed by Navigation; Navigation had the greatest advantage in the KSS score.

CONCLUSION

Navigation and Robot did improve the accuracy of alignment compared with PSI and conventional instrument in TKA, but the above four techniques showed no clinical significance in postoperative outcomes.

LEVEL OF EVIDENCE

I.

Evaluation of optimal implant alignment in total hip arthroplasty based on postoperative range of motion simulation

BACKGROUND

Dislocation after total hip arthroplasty is a frequent cause of revision surgery. This study was performed to determine the optimal implant alignment in total hip arthroplasty by simulating the postoperative range of motion.

METHODS

All operations were performed via posterolateral approach using combined anteversion of the stem and cup technique. Maximum range of motion without implant impingement was simulated in 79 replaced hips using postoperative computed tomography and the achievement of the required range of motion defined by previous studies was assessed. Optimal cup and stem alignment for impingement-free range of motion were statistically determined using the receiver operator coefficient curve.

FINDINGS

Cup inclination and anteversion, stem anteversion, and combined anteversion were 37.6°, 20.1°, 26.2°, and 46.3°, respectively. Maximum range of motion in flexion, extension, internal rotation at 90° of flexion, and external rotation were 131.8°, 42.3°, 56.4°, and 64.5°, respectively. Flexion >110°, extension >30°, internal rotation >30° at 90° of flexion, and external rotation >30° were fulfilled by 96%, 86%, 92%, and 96% of all replaced hips, respectively. Optimal implant alignment for impingement-free range of motion was 34°-43° of cup inclination, 18°-26° of cup anteversion, 17°-29° of stem anteversion, and 35°-56° of combined anteversion. Both cup and stem anteversion showed significant relationship with postoperative range of motion.

INTERPRETATION

Surgeons could gain valuable insights into optimal cup and stem alignment to perform postoperative range of motion simulations.

Comparative Cost Analysis of Four Different Computer-Assisted Technologies to Implant a Total Knee Arthroplasty over Conventional Instrumentation

Several computer-assisted technologies, such as navigation and robotics, have been introduced to Total Knee Arthroplasty (TKA) in order to increase surgical precision and reduce complications. However, these technologies are often criticized due to the increased costs and effort associated with them; however, comparative data are missing. The aim of the present study was to evaluate differences in intraoperative workflows and the related perioperative cost-profiles of four current computer-assisted technologies, used to implant a TKA, in order to gain a comparison to conventional instrumentation. For the cost analysis, additional preoperative imaging and instruments, increased operating room (OR) and planning-time, and expenditures for technical support of the equipment and disposals were calculated, in comparison to conventional TKA, for (1) standard computer-navigation, (2) patient specific instruments (PSI), (3) image-based robotic assistance, and (4) imageless robotic assistance. Workflows at four expert centers which use these technologies were reviewed by an independent observer. The total cost calculation was based on a 125 TKA per year unit in Switzerland. Computer-navigation resulted in 14 min (+23%) increased surgery time and, overall, USD 650 in additional costs. PSI technology saved 5 min (8%) OR time but it created USD 1520 in expenditures for imaging and disposals. The image-based robotic system was the most expensive technology; it created overall additional costs of USD 2600, which predominately resulted from technical support, disposals, the CT-Scan, and 14 min of increased OR time. The imageless robotic assistance resulted in the largest increase in OR-time, as it resulted in an additional 25 min (+42%) on average. Overall, additional costs of USD 1530 were calculated. Every one of the assistive technologies in this study increased the total cost of TKA when compared to a conventional technique, and the most important variables, related to cost, were technical support and additional disposables. The longer surgical times and additional surgical trays required for the techniques had a marginal effect on overall costs. This comparative cost analysis gives valuable information for future efforts to calculate the real costs of these technologies and the subsequent return on investment of each technique.

The Influence of Postoperative Coronal Alignment on Tibial Migration After Total Knee Arthroplasty in Preoperative Varus and Valgus Knees: A Secondary Analysis of 10 Randomized Controlled Trials Using Radiostereometric Analysis

BACKGROUND

Orthopaedic surgeons aim for mechanical alignment when performing total knee arthroplasty (TKA) as malalignment is associated with loosening. Loosening may be predicted by migration as measured with radiostereometric analysis (RSA), but previous RSA studies on postoperative alignment have shown contradictory results and have been limited to cemented implants and small numbers of patients. Therefore, we performed a secondary analysis of 10 previously published randomized controlled trials (RCTs) to compare migration between postoperative in-range and out-of-range cemented and uncemented TKA implants among patients with a preoperative varus or valgus knee.

METHODS

All RCTs involving the use of RSA that had been conducted at 2 centers were included. Alignment was classified, with use of the hip-knee-ankle angle (HKA), as in-range (0° ± 3°) or out-of-range (<-3° or >3°). The fixation methods included cemented, uncemented-coated, and uncemented-uncoated. Migration was measured at 3, 12, and 24 months. A linear mixed model was used, with adjustment for fixation method and clustering of patients within centers.

RESULTS

Of 476 TKA implants that had been out-of-range preoperatively, 290 were in-range postoperatively and 186 were out-of-range in either varus (n = 143) or valgus (n = 43) postoperatively. The mean migration at 3, 12, and 24 months was 0.73 mm (95% confidence interval [CI], 0.66 to 0.79 mm), 0.92 mm (95% CI, 0.85 to 1.00 mm), and 0.97 mm (95% CI, 0.90 to 1.05 mm), respectively, for the in-range group and 0.80 mm (95% CI, 0.72 to 0.87 mm), 0.98 (95% CI, 0.90 to 1.07 mm), and 1.04 mm (95% CI, 0.95 to 1.13 mm), respectively, for the out-of-range group (p = 0.07). The fixation method significantly influenced migration, with uncemented-uncoated implants migrating more than cemented and uncemented-coated implants (p < 0.001).

CONCLUSIONS

Postoperative alignment did not influence migration of TKAs in the first 2 postoperative years in patients with preoperative varus or valgus alignment of the knee. However, the fixation method significantly influenced migration, with uncemented-uncoated implants showing the greatest migration.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Robotic-arm-assisted Knee Arthroplasty Associated With Favorable In-hospital Metrics and Exponentially Rising Adoption Compared With Manual Knee Arthroplasty

BACKGROUND

Technology-assisted knee arthroplasty (KA), including robotic-arm-assisted knee arthroplasty (RA-KA) and computer-assisted (CA-KA) knee arthroplasty, was developed to improve surgical accuracy of implant positioning and alignment, which may influence implant stability, longevity, and functional outcomes. However, despite increased adoption over the past decade; its value is still to be determined.

QUESTIONS/PURPOSE

This study aimed to compare robotic-arm (RA)-KA, CA-KA, and manual (M)-KA regarding (1) in-hospital metrics (length of stay [LOS], discharge disposition, in-hospital complications, and hospitalization-episode costs), (2) characterize annual utilization trends, and (3) future RA-KA and CA-KA utilization projections.

METHODS

National Inpatient Sample was queried for primary KAs (unicompartmental/total; 2008 to 2018). KAs were classified by modality (M-KA/CA-KA/RA-KA) using International Classification of Disease-9/10 codes. A propensity score-matched comparison of LOS, discharge disposition, in-hospital complications (implant-related mechanical or procedure-related nonmechanical complications), and costs was conducted. Trends and projected utilization rates were estimated.

RESULTS

After propensity score matched to their respective M-KA cohorts, RA-KA and CA-KA exhibited shorter LOS (RA-KA versus M-KA: 2.0 ± 1.4 days versus 2.5 ± 1.8 days; P < 0.001; CA-KA versus M-KA: 2.7 ± 1.4 days versus 2.9 ± 1.6 days; P < 0.001) and in-hospital implant-related mechanical complications (P < 0.05, each). RA-KA demonstrated lower nonhome discharge (P < 0.001) and in-hospital procedure-related nonmechanical complications (P = 0.005). RA-KA had lower in-hospital costs ($16,881 ± 7,085 versus $17,320 ± 12,820; P < 0.001), whereas CA-KA exhibited higher costs ($18,411 ± 7,783 versus $17,716 ± 8,451; P < 0.001). RA-KA utilization increased from <0.1% in 2008 to 4.3% in 2018. CA-KA utilization rose temporarily to 6.2% in 2014, then declined to pre-2010 levels in 2018 (4.5%). Projections indicate that RA-KA and CA-KA will represent 49.9% (95% confidence interval, 41.1 to 59.9) and 6.2% (95% confidence interval, 5.3% to 7.2%) of KAs by 2030.

DISCUSSION

RA-KA may provide value through improving in-hospital metrics and mitigating net costs. Similar advantages may not be reliably attainable with CA-RA. Because RA-KA is projected to reach half of all knee arthroplasties done in the United States by 2030, further cost analyses and long-term studies are warranted.

[Short-term effectiveness of novel computer navigation system assisted total knee arthroplasty]

Objective

To investigate the short-term effectiveness of novel computer navigation system (Knee 3 software; Brainlab, Germany) assisted total knee arthroplasty (TKA).

Methods

Between July 2020 and December 2020, 19 patients underwent unilateral TKA assisted with Knee 3 software. There were 4 males and 15 females. The mean age was 66.3 years (range, 52-79 years). Eighteen patients were diagnosed with osteoarthritis and 1 patient with rheumatoid arthritis. Sixteen patients had varus knees and 3 patients had valgus knees. Preoperative Western Ontario and McMaster University Osteoarthritis Index (WOMAC) pain, stiffness, function, and total scores were 12.4±3.4, 2 (1, 4), 22 (18, 29), and 37 (29, 43), respectively. Intraoperatively, the medial and lateral gaps in knee extension and in 90° of knee flexion were recorded. The operation time, intraoperative blood loss, blood transfusion, and complications were recorded. The hip-knee-ankle angle (HKA), lateral distal femoral angle, and medial proximal tibial angle were measured to evaluate lower limb alignment and prostheses's alignment using X-ray films at 6 weeks after operation. Patient's satisfaction rate and WOMAC pain, stiffness, function, and total scores were investigated.

Results

Eighteen patients (94.7%) had medial- lateral gap balancing in knee extension, 18 patients (94.7%) had medial-lateral gap balancing in 90° of knee flexion, 19 patients (100%) had medial gap balancing between knee extension and 90° of knee flexion, and 18 patients (94.7%) had lateral gap balancing between knee extension and 90° of knee flexion. The mean operation time was 126 minutes (range, 100-200 minutes). The mean intraoperative blood loss was 205 mL (range, 100-400 mL). Patients were followed up 4-8 months, with an average of 6.2 months. Postoperative complications included 1 deep vein thrombosis of lower extremities and 1 cerebral infarction. X-ray films showed that the mean HKA, lateral distal femoral angle, and medial proximal tibial angle were 179.8° (range, 178°-182°), 83.5° (range, 80°-87°), and 89.5° (range, 87°-93°), respectively. At last follow-up, WOMAC pain, stiffness, function, and total scores were 3.6±1.9, 0 (0, 2), 4 (2, 6), and 9 (5, 10), respectively, which improved when compared with preoperative scores ( P<0.05). Twelve patients were very satisfied with the operation results and 7 patients were satisfied with the operation results. The overall satisfaction rate was 100%.

Conclusion

Knee 3 software can help to obtain good gap balancing and optimal lower limb alignment, with high patient's satisfaction and good short-term effecectiveness.

No difference in long-term functional outcomes or survivorship after total knee arthroplasty with or without computer navigation: a 17-year survivorship analysis

Background

The literature comparing the long-term outcomes and survivorship of computer navigation-assisted and conventional total knee replacement (TKR) is sparse. Moreover, of the available comparative studies with follow-up duration of more than 10 years, the results seem to be conflicting. The purpose of this long-term study was to compare the clinical and radiological outcomes, and implant survivorship, of TKR performed with and without computer navigation.

Methods

We retrospectively compared the results of 49 computer-navigated TKRs and 139 conventional TKRs. The mean age of the patients was 67.9 (range 52–81) years for the navigation group and 67.1 (range 50–80) years for the conventional TKR group. The mean duration of follow-up for the conventional and navigation TKR groups was 12.9 and 13.2 years, respectively. Clinical and radiographic follow-up examinations of the patients were performed at 2 weeks, 1 month, 3 months and 6 months post-operatively, and at 1-year intervals thereafter.

Results

There were no significant differences in the post-operative Knee Society knee and function score between the two groups. The mean overall deviation from neutral alignment and the radiological outliers were significantly higher in the conventional TKR group. The overall survival rates at 17 years were 92.9% for the navigation group and 95.6% for the conventional TKR group (p = 0.62).

Conclusions

Navigated TKR resulted in fewer radiological outliers; however, this did not translate to better long-term functional outcomes or implant survival.

Clinical outcomes of two-stage revision for chronic periprosthetic joint infection of the knee: culture-negative versus culture-positive

Background

The effect of negative culture on the treatment outcomes of chronic periprosthetic joint infection (PJI) is still controversial. The purpose of this study is to evaluate whether the outcomes of two-stage revision in culture-negative chronic PJI differ from those in culture-positive PJI.

Methods

The patients who received two-stage revisions due to chronic PJI during the period between 2007 and 2017 were retrospectively reviewed. The culture-negative and culture-positive PJI group included 57 cases and 79 cases, respectively. The demographic data, as well as reoperation, mortality, reinfection, and failure rates of each group were evaluated.

Results

There was a significant difference in reoperation rate between the two groups for the period from the first-stage surgery to the second-stage revision arthroplasty (p = 0.045). The reoperation rate of the culture-positive group was 25.3% (20/79) whereas that of the culture-negative group was 10.5% (6/57). Among the 136 PJI cases, 97 cases (71.3%) received reimplantation surgery (culture-negative group, 43 cases; culture-positive group, 54 cases). No significant difference was noted between the culture-negative and culture-positive groups with respect to the number of cases that did not undergo reimplantation surgery and the reoperation, reinfection, mortality, and failure rates after two-stage surgery (p > 0.05, all parameters).

Conclusions

The culture outcome had no significant effect on the outcome of the two-stage revision in patients with chronic PJI. The reoperation rate after first-stage surgery was significantly higher in the culture-positive group, but the overall failure rate did not significantly differ in both the groups. The presence of a negative culture might be a good prognostic factor for chronic PJI.

Outcomes of Computer-Assisted Total Knee Arthroplasty Compared to Conventional TKA: A Bicentric Controlled Retrospective Clinical Study

Despite the globally ascertained success of Total Knee Arthroplasty (TKA) procedure, 20% of patients are still unsatisfied with the surgery results. The purpose of the study is to identify the functional and radiological outcomes of the computer-assisted (CAS) TKA compared to the conventional technique. The clinical databases and medical records of both clinical sites were retrospectively analyzed, and then according to study time-lapse, inclusion, and exclusion criteria, eligible patients were retrieved and included. A total of 42 patients that underwent to CAS TKA (NAVI) and 61 patients that underwent to Conventional TKA (CONV) were included. The NAVI group reported a statistically significant higher surgical time. A lower intraoperative blood loss was found in the computer-assisted group, though this difference was not statistically significant. Implant survival analysis at two years did not show differences between groups during the follow-up period. At two years, follow-up postoperative intergroup analysis showed no statistically significant difference between groups. According to the radiologic analysis, the NAVI group showed comparable outcomes to the conventional group. The present study showed that there was no clinical and radiological difference between CAS arthroplasty and conventional technique.

Minimal Clinically Important Difference in Robotic-Assisted Total Knee Arthroplasty Versus Standard Manual Total Knee Arthroplasty

BACKGROUND

The purpose of this study was to determine whether robotic total knee arthroplasty (R-TKA) demonstrated evidence of improvement in minimal clinically important difference (MCID) in early (<4 weeks) and intermittent (4-8 month) patient-reported outcomes compared with manual total knee arthroplasty (M-TKA).

METHODS

A prospectively collected database was reviewed of 1160 consecutive patients undergoing R-TKA or M-TKA from December 2017 to October 2019. Primary outcomes consisted of Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS-JR) and Patient-Reported Outcomes Measurement Information System Global Health Measures of Physical Health (PH) and Mental Health (MH). Statistical analysis included MCID via the distribution method.

RESULTS

Univariate analysis demonstrated conflicting results for early MCID achievement favoring M-TKA (4-week KOOS-JR, P = .03) for the multisurgeon cohort, but favored R-TKA (4-week Patient-Reported Outcomes Measurement Information System-PH, P = .04) in the single-surgeon analysis, and the remaining outcome scores were similar. Ultimately, multivariate analysis demonstrated similar 4-week and 6-month MCID achievement in all measures. Lower preoperative scores consistently achieved MCID at a higher rate in M-TKA, although in R-TKA, the higher baseline scores improved at a rate comparable with those with lower scores in all but the short-term postoperative KOOS-JR.

CONCLUSION

R-TKA demonstrated comparable MCID achievement to M-TKA across the larger cohort. Single-surgeon comparison did show some early benefit. Confounding variables such as surgical technique, implant fixation, and responsiveness of an outcome measure may be as important as simply what tools are used during surgery. Such granular data should be sought out in future studies.

Outcomes of total joint arthroplasty in patients with depression: A systematic review

BACKGROUND

Depression has been implicated as a poor predictor of outcomes after total joint arthroplasty (TJA) of the lower extremity in some studies. We aimed to determine whether depression as a comorbidity affects the TJA outcomes and whether pain reduction associated with successful TJA alters depressive symptoms.

METHODS

A search of PUBMED was performed using keywords "depression", "arthroplasty", "depressive disorder", and "outcomes." All English studies published over the last ten years were considered for inclusion. Quantitative and qualitative analysis was then performed on the data.

RESULTS

Thirty articles met inclusion criteria (16 retrospective, 14 prospective). Three showed that depressed patients were at higher risk for readmission. Two reported that depressed patients had higher likelihood of non-home discharge after TJA compared to non-depressed patients. Four noted that depressed patients incur higher hospitalization costs than non-depressed patients. Ten suggest depression is a predictor of poor patient-reported outcome measures, pain, and satisfaction after TJA. Five suggested the gains depressed patients experience in functional outcome scores after TJA are similar to gains experienced by patients without depression. Another eight suggested that TJA improves not only function and pain but also depressive symptoms in patients with depression.

CONCLUSION

The results of this review show that depression increases the risk of persistent pain, dissatisfaction, and complications after TJA. Additionally, depressed patients may incur higher costs than non-depressed patients undergoing TJA and may have worse preoperative and postoperative patient reported outcome measures (PROMs). However, the gains in function that depressed patients experience after TJA are equivalent to gains experienced by non-depressed patients and depressed patients may experience improvement in their depressive symptoms after TJA. Patient selection for TJA is critical and counseling regarding increased risk for complications is crucial in depressed patients undergoing TJA.

Robotic-Assisted Total Knee Arthroplasty: An Assessment of Content, Quality, and Readability of Available Internet Resources

BACKGROUND

The use of robotic-assisted total knee arthroplasty (TKA) has significantly increased over the past decade. Internet content is largely unregulated and may contain inaccurate and/or misleading information about robotic TKA. Our goal was to assess the content, quality, and readability of online material regarding robotic-assisted TKA.

METHODS

We conducted an internet search for the top 50 web sites from each of the 3 most popular search engines (Google, Yahoo, and Bing) using the search term robotic total knee replacement. Each web site was assessed for content, quality, and readability. Web site quality was assessed utilizing the QUality Evaluation Scoring Tool (QUEST). Readability was assessed utilizing the Simple Measure of Gobbledygook, Flesch-Kincaid Grade Level, and Flesch Reading Ease Formula scores.

RESULTS

General risks of TKA were discussed in 47.2%, while benefits were discussed in 98.6% of all web sites. Inaccurate claims occurred at a significantly higher rate in physician/community hospital sources compared to university/academic web sites (59% vs 28%, P = .045). Web sites from university/academic web sites had the highest QUEST scores, while physician/community hospital sources scored the lowest (16.1 vs 10.6, P = .01). Most web sites were written at a college reading level or higher.

CONCLUSION

Patients should be counseled on the largely unregulated nature of online information regarding robotic-assisted TKA. Physicians and hospitals should consider revising the readability of their online information to a more appropriate level in order to provide accurate, evidence-based information to allow the patient to make an informed consent decision.

Computer assisted total knee arthroplasty: 2.5 years follow-up of 200 cases

INTRODUCTION

Computer assisted surgery in total knee arthroplasty (TKA) should improve accuracy of both femoral and tibial components placement. This study evaluated the functional outcomes of computer navigated total knee arthroplasty through the Knee Society Score (KSS) and Tegner Lysholm Knee Scoring Scale (TLKSS).

MATERIALS AND METHODS

Between September 2007 and February 2013, 180 patients (200 knees; 109 females and 71 males; mean age: 64 years) undergoing computer-assisted TKA were recruited. Plain radiographs and CT scans were performed post-operatively to evaluate alignment. The clinical outcomes were measured using the KSS and TLKSS pre-operatively and after 6, 12 and 36 months.

RESULTS

The mean follow-up duration was 2.5 years. The mean tourniquet time was 72 ± 13.4 min, and patients received an average of 0.6 ± 0.82 units of blood after surgery. The average preoperative KSS functional score of 44.6 ± 13.7 improved to 80.4 ± 16.4 after 2 years. The average preoperative TLKSS improved to 71.4 ± 13.5 after 2 years. The mechanical axis was within ±3° in all patients. No axial malalignments were observed on TC Scan. Three patients (1.6% of cases) required revision.

CONCLUSION

Computer assisted TKA allows reproducible alignment and kinematics, reducing outliers, provides ligament balancing and ensures good short term outcomes in terms of KSS functional score and TLKSS.

New Technologies in Knee Arthroplasty: Current Concepts

Total knee arthroplasty (TKA) is an effective treatment for severe osteoarthritis. Despite good survival rates, up to 20% of TKA patients remain dissatisfied. Recently, promising new technologies have been developed in knee arthroplasty, and could improve the functional outcomes. The aim of this paper was to present some new technologies in TKA, their current concepts, their advantages, and limitations. The patient-specific instrumentations can allow an improvement of implant positioning and limb alignment, but no difference is found for functional outcomes. The customized implants are conceived to reproduce the native knee anatomy and to reproduce its biomechanics. The sensors have to aim to give objective data on ligaments balancing during TKA. Few studies are published on the results at mid-term of these two devices currently. The accelerometers are smart tools developed to improve the TKA alignment. Their benefits remain yet controversial. The robotic-assisted systems allow an accurate and reproducible bone preparation due to a robotic interface, with a 3D surgical planning, based on preoperative 3D imaging or not. This promising system, nevertheless, has some limits. The new technologies in TKA are very attractive and have constantly evolved. Nevertheless, some limitations persist and could be improved by artificial intelligence and predictive modeling.

Clinical value of CT-based patient-specific 3D preoperative design combined with conventional instruments in primary total knee arthroplasty: a propensity score-matched analysis

Purpose

To evaluate the operation and early clinical effect in primary total knee arthroplasty (TKA) about the novel combination of CT-based patient-specific three-dimensional (3D) preoperative design and conventional osteotomy instruments, compared with the conventional method.

Methods

After a 1:1 propensity score-matching (PSM), patients were matched to the novel technique group and the conventional group, 109 cases in each group. The conventional group adopted a preoperative design based on a full-length radiograph (FLX) and received TKA with conventional osteotomy instruments. The novel technique group used a CT-based patient-specific 3D preoperative design combined with conventional osteotomy instruments; during the surgery, the femoral entry point, femoral valgus osteotomy angle, the fix point of tibial plateau extramedullary guide pin, and the position of tibial extramedullary positioning rod were accurately selected according to the preoperative 3D design to ensure accurate intraoperative implementation. The lower limb alignment, component position, operation time, tourniquet time, hospital stay, blood loss volume, incidence of postoperative complications, visual analog scale (Vas) score, and New Knee Society Score System (NEW-KSS) at 1 day before operation and 1, 6, and 12 months after operation were recorded and compared.

Results

The novel technique group was significantly better than the conventional group in controlling lateral tibial component angle (LTC) (P < 0.001), and the novel technique group had lower percentages of hip-knee-ankle angle (HKA) outliers (P < 0.001) and overcorrection (P = 0.003). The operation time, tourniquet time, and hospital stay of the novel technique group was shorter (P < 0.05). In 1 month after the operation, the novel technique group achieved a significantly better VAS score (P < 0.05), but a similar NEW-KSS score (P > 0.05) when compared with the conventional group. But in 6 and 12 months after surgery, no statistical differences were seen in the above two scores (P > 0.05).

Conclusion

The novel technique of CT-based patient-specific 3D preoperative design combined with conventional instruments can improve the accuracy of osteotomy in primary total knee arthroplasty, with benefits of significantly reducing pain and rapid recovery during the early postoperative period, but having no obvious effect on outcome after a 1-year follow-up.

Effects of Teriparatide on Treatment Outcomes in Osteoporotic Hip and Pelvic Bone Fractures: Meta-analysis and Systematic Review of Randomized Controlled Trials

The primary objective of this study was to evaluate randomized controlled trials (RCTs) that have reported the effects of teriparatide on bone-healing in osteoporotic hip and pelvic bone fractures to determine the efficacy of teriparatide in lowering the rate of treatment failure. A total of 2,809 studies were identified using a comprehensive literature search (MEDLINE [n=1,061], Embase [n=1,395], and Cochrane Library n=353]). Five RCTs were included in the final analysis. Treatment failure rates at the last follow-up of osteoporotic hip and pelvic bone fractures between the teriparatide and control groups was the primary outcome. Treatment failure was defined as non-union, varus collapse of the proximal fragment, perforation of the lag screw, and any revision in cases due to mechanical failure of the implant during the follow-up period. The number of treatment failures in the teriparatide and placebo groups were 11.0% (n=20 out of 181) and 17.6% (n=36 out of 205), respectively. Although the rate of treatment failure in the teriparatide group was lower than that in the control group, this difference was not significant (odds ratio, 0.81 [95% confidence interval, 0.42–1.53]; P=0.16; I²=42%). This meta-analysis did not identify any significant differences in the rate of treatment failure between the teriparatide and control groups at final follow-up. Based on these results, we believe that there is a lack of evidence to confirm efficacy of teriparatide in reducing treatment failures in osteoporotic hip and pelvic bone fractures.

Clinico-Radiological and Functional Results of the Navigated Gradius (Gradually Reducing Radius) Knee Prosthesis at Short to Mid-Term Follow-Up

BACKGROUND

Navigated total knee replacements (TKR) have shown better knee function and quality of life. It also reduces revision rates. The aim of our study is to evaluate short to mid-term clinico-radiological and functional results, survival rate and complications of Gradius knee prosthesis implanted using computer navigation.

METHODS

We retrospectively reviewed 120 Gradius knee prosthesis, implanted in 68 patients (52 bilateral TKR and 16 unilateral TKR) and followed from Jan 2015 till Jan 2020. Pre-operative & post-operative radiographs, knee society scores (KSS), range of motion (ROM), deformity assessment and gait video recordings were done for all patients.

RESULTS

The mean follow-up was 3.8 years (minimum 2-5 years).The mean ROM was 2° (0-10) extension to 135° (128°-138°) flexion. The KSS pain score improved from mean of 38.3 (range 26-44) to 90.4 (mean 88-92). The KSS functional score improved from 36.2 (range 28-39) to 92.6 (range 86-94). All patients had excellent to good function during successive follow-ups. The coronal alignment improved from 8° varus to 0.3° varus. Sagittal alignment was corrected from 8° (4°-18°) preoperatively to 2° (0°-8°) postoperatively.

CONCLUSION

At mid-term our series outlines the better functional and radiological results of Gradius knee prosthesis using navigation as a tool. We recommend a prospective randomized controlled trials comparing navigated versus non-navigated for Gradius knee prosthesis with long-term follow-up.

Comparison of the clinical effects of computer-assisted and traditional techniques in bilateral total knee arthroplasty: A meta-analysis of randomized controlled trials

Background

It is unclear whether there are individual differences in the long-term efficacy of computer-assisted and traditional total knee arthroplasty. The purpose of this study was to perform a meta-analysis comparing the same individuals undergoing computer-assisted and traditional total knee arthroplasty separately to determine whether computer-assisted total knee arthroplasty can provide better lower extremity radiographic results and clinical outcomes.

Methods

We searched literatures to identify relevant randomized controlled trials comparing the effects of computer-assisted and traditional methods in bilateral total knee arthroplasty. After screening, quality evaluation and data extraction according to inclusion and exclusion criteria, the quality and bias risks of the included studies were evaluated. The meta-analysis compared the radiographic results, functional outcomes and complications of the two techniques.

Results

Six clinical controlled trials were included, with total of 1098 patients. The meta-analysis showed that the accuracy in terms of the mechanical axis of the lower extremity, the sagittal alignment of the femoral component and the coronal alignment of the tibial component in computer-assisted total knee arthroplasty was significantly better than those in traditional total knee arthroplasty. There were no differences in the functional results, revision rates or aseptic loosening rates between the two techniques.

Conclusion

After excluding individual differences such as bone development and bone quality, although computer-assisted techniques can better accurately correct the mechanical axis of the lower extremity and the position of prosthesis implantation than traditional techniques, there is no significant difference in the functional results and revision rate of bilateral total knee arthroplasty in the same individual.

Computer-navigated versus conventional total knee arthroplasty: A randomized controlled trial protocol in China

BACKGROUND

The literature lacks studies that confirm whether the improved radiographic alignment that can be achieved with computer-navigated total knee arthroplasty (TKA) improves patients' activities of daily living or the durability of total knee prostheses. Thus, in this protocol, we designed a randomized controlled trial to compare implant alignment, functional scores, and survival of the implant using computer-assisted surgery versus a conventional surgical technique.

METHODS

This prospective, blinded randomized controlled trial was conducted at our single hospital. This study was approved by the ethics committee of Jiaxing Second Hospital. The patient inclusion criteria were age 20 to 80 years' old, a body mass index of ≤35 kg/m, and consented for primary knee arthroplasty performed through a medial parapatellar approach by the senior author. We randomized consented study participants on a 1:1 ratio to 1 of 2 study groups using a computer-generated list of random numbers in varying block sizes. The primary outcome in this study was the Knee Injury and Osteoarthritis Outcome Score. Secondary outcomes were the Knee Society Score, Western Ontario and McMaster Universities Osteoarthritis Index, complications, and range of motion together with alignment and rotational positioning of the implant. Statistical significance was defined as a P value of ≤0.05.

CONCLUSIONS

Authors hypothesized that computer-assisted surgery in primary TKA improves implant alignment, functional scores, and survival of the implant compared to the conventional technique.

Threshold for Computer- and Robot-Assisted Knee and Hip Replacements in the English National Health Service

OBJECTIVES

To estimate threshold prices for computer- and robot-assisted knee and hip replacement.

METHODS

A lifetime cohort Markov model provided the framework for analysis. Linked primary care and inpatient hospital records informed estimates of outcomes under current practice. Outcomes were estimated under a range of hypothetical relative improvements in quality of life if unrevised and in revision risk after computer or robot-assisted surgery. Threshold prices, a price at which the net health benefit from funding the intervention would be zero, for these improvements were estimated for a cost-effectiveness threshold of £20 000 per additional quality-adjusted life-year (QALY) gained.

RESULTS

For average patient profiles under current knee and hip replacement practice, lifetime QALYs were 10.3 (9.9 to 10.7) and 11.0 (10.6 to 11.4), with costs of £6060 (£5947 to £6203) and £6506 (£6335 to £6710) for knee and hip replacement, respectively. A combined 50% relative reduction in risk of revision and 5% improvement in postoperative quality of life if unrevised would, for example, result in QALYs increasing to 10.9 (10.4 to 11.3) and 11.6 (11.2 to 12.0), and costs falling to £5880 (£5816 to £5956) and £6258 (£6149 to £6376) after knee and hip replacement, respectively. These particular improvements would have an associated threshold price of £11 182 (£10 691 to £11 721) for knee replacement and £12 134 (£11 616 to £12 701) for hip replacement. The 50% reduction in revision rate alone would have associated threshold prices of £1094 (£788 to £1488) and £1347 (£961 to £1842), and the 5% improvement in quality of life alone would have associated threshold prices of £9911 (£9476 to £10 296) and £10 578 (£10 171 to £10 982).

CONCLUSIONS

At current prices, computer- and robot-assisted knee and hip replacement will likely need to lead to improvements in patient-reported outcomes in addition to any reduction in the risk revision.